It is known that the stockings discharged from the machines which produce them, are slipped on appropriate shapes so as to cause them to take up a well stretched configuration and are therefore suited for carrying out the successive operations, such as the detection of the garter line, in order to operate the precise alignment of two stockings to be united to form a pantyhose article.
Also known is the fact that at the end of its fitting over the shape, each stocking exhibits a significant number of wrinkles which must be manually eliminated by an operator who performs an operation which is known with the jargon word "pinch": the fabric of the stocking is held between the thumb and forefinger tips of an operator's hand, in correspondence of the stocking portion to be stretched and, afterwards, the thus retained stocking is subjected to a pull, transversally to the support shape, and finally released. In this way, the stocking is caused to stretch on the relevant shape with consequent disappearance of the wrinkles: this operation having to be repeated in the presence of many wrinkles.
However, since this operation is carried out by hand, it requires the presence of at least a skilled operator during each work shift, which implies the rise of the manufacturing cost of the finished product. In addition to this, if the degree of attention by the operator grows tired, the quality of the finished product results markedly impaired.